NECA Custom mask for classic predator! Noobie help!

Hello and Good day FR! I would like to ask the pro's and vet's out there what would be the best material to create a NECA size custom predator classic mask, I wanted to actually do my first custom with a battle damage classic predator only on its mask. T------T please kind monsieur's help regarding this one. Someone told me to use a plumber putty as a base or a tamiya ceramic putty then mold it, problem is I don't have any molders for the mask! Recently I've been browsing the net and I've found out customizers creating thier own mask but wouldn't give me an idea on what material theyve been using. Really appreciate it guys! Thanks again!

I sculpted it using an all purpose epoxy. the brand is "cord" I think it's only available here in our country but you can use other two part epoxy as well. you can also try using sculpeys or apoxy sculpt. the tricky part is sculpting the basic shape of the mask without the sculpt sticking permanently to the figure.

I covered the face of the neca pred with baby powder first so that the sculpt won't stick to the figures face. after it hardened, I removed it and now I have the basic shape of the mask. I sculpted another layer of details over it, let it dry, and then repainted it.

here're some WIPs.

the sculpted details were then further sanded down and trimmed with a detailing knife (cutter blade)